Plants are vulnerable to attack from insects and disease, which can cause significant damage and economic loss. One common method of protecting plants is to spray their leaves with a liquid pesticide. However, to be most effective, the liquid pesticide should be applied to all exposed surfaces of the plant. This is especially true for contact pesticides, which generally only kill pests as a result of direct contact. Conventional sprayers deliver a heavy volume of spray with such force that outer leaves collapse, thereby leaving the underside of the leaf unsprayed and/or leaving dense inner foliage growing within the outer leaves unsprayed.